1. Field of Invention
The present invention relates to a method of manufacturing a semiconductor device. More particularly, the present invention relates to a method of manufacturing a photo sensor.
2. Description of Related Art
A “Sensor” detects heat, light or magnetic fields and converts the detected physical parameter into electronic signals. By using the signal generated by the sensor, the user can obtain information therefrom.
According to the above, the data can be produced by a photo sensor that generates a current with light. The photo sensor can be divided into two parts, a transistor and a diode. The mechanism of the photo sensor is that the light is directed to the diode to generate a current, and then the current is amplified from tens to hundreds of times to produce a stronger signal.
However, in the conventional structure of the photo sensor, the material of the insulating layer used to cover the diode usually is silicon nitride, silicon oxide, or silicon oxy-nitride. Nevertheless, these materials cannot provide good insulation. In addition, since both sides of the diode are easily oxidized into silicon monoxide, the diode cover is degraded and current leakage from the diode through the insulating layer occurs. Furthermore, the conventional material for the insulating layer cannot provide good flatness. Therefore, there is a need to develop a photo sensor to prevent current leakage and to improve the electrical property of the photo sensor.